Apparatus for the manufacture of screws



vJuly 1 1930- P. l.. sTENMN 1,768,801

. 'I APPARATUS FOR THE MANUFACTURE OF SCREWS Filed Dec. 8, 1925 Sheets-Shea?I 1 ,Lea/lara' jfs/7016" INVENTOR ATTORNEY,

Jll'ly l, 1930- P. L.. sTENMAN 1,758,801;

APPARATUS FOR THE MANUEACTURE F scnws Filed Dec. 8. 1925 2 Sheets-Sheet 2 E, aanafd 5+en man.

-INVENTOR means-orcutting threads upon? screw blanks 2ER LEONARD smit-MAN,

or s'rociruonizr,A swnpniv;

Arrnnnmosron THE MANUFACTURE orfscitnws Application v led December My invention relates to the manuifacturey of screws,v and has particular reference to. v an of cutting tools.

improved apparatus comprising av pluralityV The subjectmatter disclosed by the accom@ panying drawing eXcept that. illustrated by lligures 5 to 8 inclusive is'taken from my copending application, lerialv No. 667,818, v filed October 11,1923; Anv objectof the invention is to provide inthe course of a single operation, whereby the capacity of the machines will be increased andthe costiof manufacture correspondingly reduced. Y f

As setvforth more fully in the said copending application, I achieve-this'object by providing aplurality ofcutting tools,v each one through the-initial cut made bythe rst tool,

across the'screw blank.' In the prior application 30 claim various modifications embodyingapluralityof cutting toolsfin radial disposition relative to the blank.

have illustrated. by way 'of example several constructions which will disclose the nature of my invention,

Y Fig. l is a side view, partly in sectiomiofone V f form of construction; Fig. 2 is a view similar to Fig. l. showing a slight modification, and for the sake of clearness;

form of construction;

construction and [Figs 7 `and V8 are end andside viewfie-Q spectively of a simllar formof construction.

50 Referringl to the drawings, and particwv of which may 'have one or morecuttingedges, f and means 'for causing relative movementV o i'v the toolsfand the screwblankA so that the' tools lwill follow each other in succession a pluralityof cut-` ting tools was referred toy generally, andI in Vthisapplication,V I purpose to describe and the tools along the blank will cut In they accompanying drawings wherein'l` with parts'pmitted s, 1925. sentirne. 74u20., o'

carrier 71-0" having "radially disposed guide waysll on one face thereof and tools VlQ'disfk ably ymounted for axial movement thereoiin bearings, not shown. The carrier is lprov vided with anaxialbore or opening llwith its open yendadjacent the cuttingedges with the Vt\; ols, where by axial movement of the cai-,j rier` "10 with .'respeotxto a screw blank (not shown), suitably mounted yfor (rotation Vinj a' chuck? (notshown), wilhallow the tools to Inovef'longitudinally alongthe blank, the e movement. I i

opening rk 114 receiving the blank during such cutting edgesl'' whichare disposed alongla thisA helixto the. other are arranged in their guide ways '11j in positions at increasing dis-y -f tances from the'aXis of'theblank. In other wordsr the cutting edgesarearrangedI along Y a Vconicalspiral whereby longitudinal move? ment of Vthe, toolsalong the blank 'in timed relation tothe Vrotation 'of theblank'will causey the toolstocut successively through a helical f cut made thev Iirst tool, `each succeeding tool; cutting a'littlede'eper so'tha't one motion lof' a complete Vscrew thread on the blank. S j' o -f or" the purpose of pointing theV end of'- t-l 1e screw,jY and @for V withdrawing the tools from thefblan'k at'theiinner end of the thread, and for similar purpose of shaping the periphery `of"thesorewin any vdesired manner (fa's for. `e`xa1nple`inthe case ofwood screws as kcompat) ed ""'withnmachine screws), means are their guide waysat.predetermined intervalsi- Thus in. Figfh I have shown the tools articu.v

, l latedto Vlevers 16whichjarel pivoted at V17' to Fig. 5 is a plan view of a porticnoi Fig.' 35j Fig. 6 is an end view of, 'another form' fof' the tool carrier and'whosfe lrear ends are suit: ably curved'and shaped as4 at l8rto be guided, by?, qain'gsurgface 19 on a xed Lksleeve 20. In llizg'gfll the tools 'are shown in a positionabont ymidway oftheirtravel along va screw blank.

The continuation ofthe axial movement of {providedor nmving*the 'tools radially in Figs. 8 and 4 are side and end Views respecitively,` lpartly in section, illustrating another zo helizyand successive tools from oneend""o '1`. f'

k"cause the ends 18 "eventually to engage and.

are carrier 1o (to the right in Fig. 1) win In 2 I 'have shownV diagrammatic-ally Y how a constrnction 'substantia"1yY lsimilar tothat shown in Fi Imay embody cam sur faces 22 enga ed irectly by the rear ends of the tools 12, w ereby the necessity for a sleeve 20 and levers `16 is eliminated.

In Fig. 3 I have shovvn'a construction in fwhich `a sleeve23 is carried bythe carrier internal il 11 are Vprovidedvvith orapivots 27movab1eV infand guided by theglrooves y26. Suitable i tating screw blank, the combination of a plu-` 10' rotatably with respect thereto'by virtue i {id21-10'; "The front surfaceof 'theA sleeve 23 is vided' with"A `suitably curved or cam grooves 26, and' the rear portions of the tools radial guide ways 28 are again' provided on 3 the front face of the carrier 10` toreceive blank (not shown), and Ihve illustratively n in thecam caves-26 f' effected through` the agency. of the lever Voperating `substantially as described with 'fin Figure l, is,` inr this case forked and pro-V vided with adjustable screws 37 having coni-f C21! PQitS pivotally engaging conical recesses l Q d D 381D thetool bar 1211.

the tools. `At one oint in the peri heryy of the sleeve123`, the. atter is provide with a' in opivot29. movable vin `andV guided bv 4a Exedcam slot 30. `Means are agamvprovi ed for causing; akial movement of the carrier in timed relationfto the rotation of the screw shownafpinorl pivot 31 carried by a .rear-v wardly .projecting shaft portion 32f1of the ,carrier and engaging a cam track 33 ina F barel cam`34 rotated at a suitable speed ithfrespectl'lto the rotation ofthe screw "fAkxialinovemnt vof the carrier'by meansk ofthe rotation ofthe cam`.34"wi1l cause` the sleeve 23 to bev rotated Aslightly at predeterf ofnvthe pin t e cam slot 30. Suc rotationof the sleeve relative to the carrier'vvill cause the tools tovmovein radial directions by #virtue of the enga 'ements of the ins 27 before set orth.

In the arrange ent illustrated in Figure 6,

12t illustrated mounted fadj-ustably :on a

tool bar` 12n `which is'adapted to slide in the.

slot or groove 49 oftheftool guide 35; V'Ade Vm@ or v,its retraction from sad 'work piece is d reference toFigurev 1 of the drawing and it willbe clear thatfthff'endof thelsad leverrv corresponding to outelf'arm of, the'lever 16 Q y o y l rotatingscrew blank the combination of a plurality of "cutting tools disposed radially` Adjustable screws 36,` havingthreadedy enmined intervals b virtue of theenga ement or the purposes erein?.

the tool tovvardslthe work piecel 50,."

.and means for simultaneously movin Vcutting edges of said tools radially o said gagement with lugs 53 protruding from the face of the ,tool holder guide and bytheir Vmeans the said guide may be adjusted to attack the Workjeither in'a radial direction V`'39 are" enga-gedattheir ear ends 4011 by cam slots 4111 provided'in a fixed sleeve 42u.

"It will bev obvious that various modifications in the details as herein described and illustrated in orderto explain the nature of ymy invention may be made Without departing from the spirit and scope of my invent-ion as set` .forth in the appended claims. i

Iclaim: .Y A

l. In a. machine for cutting threads in` afro- Vralityof cutting tools'A disposed radially `of the axis of the saidvblank and having similar cuttingedges disposed along a conical spiral about the axis ofsaidblank and meansfor simultaneously moving said cutting edges radiallyvof said blankat diierent speeds.l 13." Ina machine for cutting threads in a rotating screwblank, the combination` of a pluralityof cuttin tools'dis osed radially of the axisof said lank andV aving similar cutting edges dis osed alon a conical spiral about `the axis o said blan and means for simultaneously moving said cuttingedges radially ofsaidblankat different speeds, said means'comprising a pluralityof diierentl shaped cam Vtracks and means on said too s Vco-operating with' said cam tracks.

l 4. Ina'rmachine for cutting threads in screw blank theV combination of a luralit of cuttin tools disposed radially o theaxis of fsaid lank and having similar' cutting edges disposed along a conical spiral about the axis of said blank, means for moving said tools asa unit long fitudinally of said blank, the

blank during said longitudinal movement of said `tools.` i A y5. In a machine for cutting threads in a of theaxis of said blank and having similar cutting edges disposed along a conical spiral about the airis of said blank, means for movmeans for moying'said tool head longitudi- Y nally of said blank Vin timed relation to said l v ingsaid toolsfas a unit longitudinallyY of" said blank, and'meansv for simultaneously moving 'thecutting edges of said tools lat different speeds radially of said blankduringj said longitudinal movementof said tools.-

6. Ina machinefor cutting'thre'adsin. a; rotating screwblank vthe combination of a'l y plurality of cutting tools ydisposed Yradially of the axis of said iblankand having similar cutting edges disposed along al conical spiral about the axisiof said blank, means for mov- Y ing said tools as a unit longitudinally of said blank, and means for simultaneously moving the cutting edges of said tools'at different speeds radially of said blank duringsaidlongitudinal' movement of said tools, lsaid means comprising a pluralityof differently shaped cam tracks and means on said tools -co-operating With said cam tracks.

7. In a machine forcutting threads ina screw blank, ini combination, a .tool head,

rotation, a plurality of cuttin'gtools disposed in 'said vtool head substantially radially of said blank, and means for *moving saidtools f substantially radially of said blank at dit#y ferent speeds during the cutting operation,

whereby the pointed end and the shankof the Q screw are formed in a continuous operation.

In testimony whereof I ali/ix my signature.

PER LEONARD STENMAN. 

